macOS build instructions

[o0101]

Hello, I like this - this is SO cool! I just got it to build on macOS. Very easy.

One thing I want to add that I think might be omitted from current build instructions was needing to install:

brew install --cask macfuse
brew install genext2fs

I really want to write some software for this.

[ADKaster]

You shouldn't install both of those. Pick one. This is outlined in https://github.com/SerenityOS/serenity/blob/master/Documentation/BuildInstructionsMacOS.md

Were there any details in that doc that you feel are missing?

[o0101]

Hey @ADKaster thanks! Sorry I hilariously missed that.

I guess you could break the options out of the code block into a separate section for greater clarity.